It is known that certain olefinically unsaturated compounds containing an activating or polar group may undergo thermal cyclo-addition reactions with allene to form correspondingly substituted methylene cyclobutene derivatives, for example, the known reaction of acrylonitrile, methyl acrylate, acrylic acid and styrene with allene to form the corresponding cyano-, carbomethoxy-, carboxy- and phenyl-substituted methylene cyclobutanes. It also is known that allene will dimerize thermally to yield a dimethylene cyclobutane.
The occurrence of these reactions appears to depend upon the activating effects of the polar substituents, upon the presence of the aromatic phenyl group in the case of styrene, or upon the active nature of the double bonds in the case of allene itself. We are not aware of any instance in which allene or a homolog of allene has been successfully reacted with an olefin hydrocarbon containing four or more carbon atoms, that is devoid of such activating groups. Indeed, it appears that simple thermal cyclo-addition of allene to alkenes is not possible to achieve, products of cyclodimerization or other polymerization of the individual reactants being exclusively formed.